Colorado River Uses and Losses

Colorado River System Consumptive Uses and Losses Reports

The main stem of the Colorado River rises in the Rocky Mountains of Colorado, flows southwesterly about 1,400 miles and terminates in the Gulf of California. Its drainage area of 242,000 square miles in this country represents one-fifteenth of the area of the United States. Water is used for irrigation, municipal and industrial purposes, electric power generation, mineral activities, livestock, fish and wildlife, and recreation. Large amounts are exported from the system to adjoining areas.

The Colorado River Basin Project Act of 1968, Public Law 90-537, directs the Secretary of the Interior to “make reports as to the annual consumptive uses and losses of water from the Colorado River System after each successive five-year period, beginning with the five-year period starting on October 1, 1970. Such reports shall be prepared in consultation with the States of the lower Basin individually and with the Upper Colorado River Commission and shall be transmitted to the President, the Congress, and to the Governors of each State signatory to the Colorado River Compact.”

These reports reflect the Department of the Interior’s best estimate of actual consumptive uses and losses for each year within the Colorado River Basin. The reliability of the estimates is affected by the availability of data and the current capabilities of data evaluation.

The reports include a breakdown of the beneficial consumptive use by major types of use (except mainstream reservoir evaporation), by major tributary streams, and, where possible, by individual States.